SYDNEY (Reuters) - Elephant seals swimming under Antarctic ice and
fitted with special sensors are providing scientists with crucial data
on ice formation, ocean currents and climate change, a study released
on Tuesday said.

The seals swimming under winter sea ice have overcome a "blind-spot"
for scientists by allowing them to calculate how fast sea ice forms
during winter.

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Sea ice reflects sunlight back into space, so less sea ice means more energy is absorbed by the earth, causing more warming.

"They have made it possible for us to observe large areas of the
ocean under the sea ice in winter for the first time," said co-author
Steve Rintoul from Australia's Commonwealth Scientific and Industrial
Research Organization (CSIRO).

"Until now, our ability to represent the high-latitude oceans and
sea ice in oceanographic and climate models has suffered as a result,"
said Rintoul, who also works with the Antarctic Climate and Ecosystems
Cooperative Research Centre in Hobart.

The elephant seals have provided scientists with a 30-fold increase
in data recorded in parts of the Southern Ocean, said the study by a
team of French, Australian, U.S. and British scientists and published
in the Proceedings of the National Academy of Sciences.

Between 2004 and 2005, the seals swam up to 65 kilometers (40 miles)
a day, supplying scientists with 16,500 ice profiles. The seals dived
to a depth of more than 500 meters (1,500 feet) on average and to a
maximum depth of nearly 2 km (a mile).

"If we want to understand what's going to happen to climate in the
future we need to know what the sea ice is going to do. Will there be
more or less and will it form more or less rapidly?" Rintoul told
Australian Broadcasting Corp. radio.

The experiment involved 85 seals with sensors attached to their heads.

"They measure temperature and salinity as a function of depth as they dive down and up through the water column," he said.

"From that information we can determine what the ocean currents are
doing and so they provide us with a very detailed record of how
temperatures and salinity's changed," he added.

The polar regions play an important role in the earth's climate and
are changing more rapidly than any other part of the world, with the
Southern Ocean warming more rapidly than the global ocean average.

Sea ice not only affects the amount of energy reflected back into
space, but also the amount of dense water around the Antarctic which
drives ocean currents that transports heat around the globe.

Sea ice also provides a critical habitat for krill, penguins and seals.